Mojo Maritime, leading British tidal energy marine operations specialists, and IKM Subsea, Norwegian ROV manufacturer and operator, have jointly secured a significant EU Horizon 2020 Grant to support a €1,200,000 R&D project to develop an ROV for use in high energy tidal sites, and capable of being operated from Mojo’s ground breaking tidal energy vessel, the Hi Flo 4 (HF4).
A significant proportion of overall tidal energy costs are in array installation and, between 2012 and 2014, Mojo Maritime designed and developed the HF4, an offshore construction vessel (OCV) capable of lifting the heaviest envisaged tidal turbines and of dynamically positioning in up to 5.0 ms-1 (10 knots) of tidal stream. These operational advantages will feed through into installation benefits, and Mojo’s early analysis using Mermaid™ shows that in medium energy tidal sites HF4 can install tidal arrays in half the time and at a third of the cost of conventional methods. HF4 thus offers the possibility of levilised costs of energy for tidal arrays of £118 per MWH, already below that of many envisaged offshore wind projects, and Mojo is now working with its ship-owning partner, Hammonia Reedeira, to select a yard to build the first-of-class HF4, with an anticipated delivery date target of late 2016.
A next step in reducing tidal energy levilised costs is improving the performance of key installation tools, such as ROVs, which are used not only for turbine and foundation installation, but also for cable touch-down monitoring. Conventional ROVs are generally designed to operate in subsurface currents of up to 1.5 ms-1 but, in Mojo’s experience, many struggle above 1.0 ms-1. Conventional ROVs are thus a key operating limitation in the design (and cost) of the marine operations for tidal energy installations, where subsurface current speeds of 5.0 ms-1, are the norm in high energy tidal sites.
For this reason, Mojo and IKM joined forces in mid-2014 to bid for EU funding, from the Maritime Technologies (MARTEC II) call, to develop a HF ROV capable of being operated from the HF4 in high energy tidal sites. Mojo’s extensive tidal technology installation background complements IKM’s ROV manufacture and operations experience including the design, build and operation of modern WROVs, such as IKM’s pictured Merlin WR200, intended to be the most efficient and reliable work class ROV on the market.
The two companies target is to develop a basic design for an HF ROV that is capable of then being manufactured according to a schedule that will align with the envisaged build schedule for the HF4 ship.
With its genesis in the tidal energy sector, the HF4 vessel is highly optimized and offers cost effective performance in wide range of applications, including offshore wind and oil&gas. It is therefore anticipated that the HF ROV will operate from both HF4 and OCV’s in a range of offshore operations and conditions. The companies were awarded the funding at the end of 2014, granted as part of the EU’s Marine Technology II Horizon 2020 programme, and administered by InnovateUK in the United Kingdom, and work began in earnest on the project on 5 January 2015 on the HF ROV, and will continue through to the end of 2015.